Grid terminal pick-up plate



Aug. 21, 1956 COLBY 2,760,128

GRID TERMINAL PICK-UP PLATE Filed Nov. 3. 1954 4 U a d I 3 1u l2 Q1 5 l3 INVENTOR I I I; 3 ROBERT A. 001.5)

A T TOR/VE Y United States Patent GRID TERMINAL PICK-UP PLATE Robert A. Colby, Marion, Iowa, assignor to Collins Radio Company, Cedar Rapids, Iowa, a corporation of Iowa Application November 3, 1954, Serial No. 466,625

2 Claims. (Cl. 317257) This invention relates to vacuum tube sockets and more particularly to such sockets employing by-pass condensers.

Priorly, sockets employing by-pass condensers have incorporated tubular condensers in the tube sockets around socket terminals. In high frequency circuits employing electron tubes, to obtain proper circuit operat-ion, some :of the tube elements must necessarily be connected to ground at the desired frequency. This connection should not comprise a ground connection for direct current and it is customary to use a condenser of the proper capacitance to bypass the high frequency currents to ground. There are disadvantages to connecting an ordinary condenser in a normal manner as a by-pass condenser, the primary one being that the leads connecting the terminals and the bypass condenser create an inductive impedance. This inductive impedance becomes larger as the frequency increases and at high frequencies may completely eliminate the ground connection desired. This invention provides a means for using one by-pass condenser to connect the desired tube elements to ground at high frequency with very short and very broad leads or connections, thereby minimizing any inductive eifects.

It is an object of this invention to provide an eifective means of connecting various terminals of a vacuum tube to ground through a by-pass condenser.

It is another object of this invention to provide this connection at very high frequencies and minimize the inductive effects of such connection at very high frequencies.

It is a further object of this invention to provide this connection between the tube elements and ground in an economical manner. It is a further object of this invention to provide for readily connecting various terminals of the tube socket to said by-pass condenser.

Other objects and advantages of this invention will be apparent when the following description is read in conjunction with the drawing, in which:

Figure 1 is a bottom view of the tube socket and its mounting plate with the terminal plate and bypass condenser in position.

Figure 2 is an exploded side view of these same elements and Figure 3 is a side elevation of this invention in position on a tube socket.

The socket structure as shown in Figure 1 is held in position in the terminal plate 8 by a flange 7. This plate 2 is a normal terminal plate and is provided with ears a to fasten the plate to a chassis. The socket is composed of insulating material and is formed with indentations 3 which fit into apertured ears on the terminal plate 2. Socket 5 has prong receiving recessed contacts 13, one of which is shown in Figure 3. Socket 5 has a variable number of contact projections for terminals extending from its lower surface, of which contact projection 12 is one. This projection 12 is bent from the vertical position of the remaining terminals to align with the lug 10 on the terminal pick-up plate 3. This iug 10 and terminal 12 ice provide a connection for external elements if such connection is required by the circuitry in which the tube is being used.

The contact terminals are electrically connected to the prong receiving contacts on the face of the tube socket. Terminal pick-up plate 3, which is basically circular, has lugs or projections on its outer periphery to connect the plate with the desired terminals of socket and has cut- Way sections in its outer periphery opposite the terminals which are not to be connected to plate 3. This pick-up plate 3 has a circular section removed at its center (as shown in Figure 2) to receive the button by-pass condenser 6. This condenser has a lug 4 for connection to ground or to an inter-stage shield as desired. Plate 3 and condenser 6 are soldered or in some manner electrically connected so that terminals on the socket are now connected to ground at radio frequencies through the plate 3 and the condenser 6.

The plate 3 provides the short leads or projections 11 to connect the condenser 6 and the terminals of the tube socket, thereby minimizing inductive reactance to high frequency currents. The plate 3 and condenser 6 operate as described herein as a low impedance connection for frequencies up to several hundred megacycles with miniature tubes. Thus, the invention provides a connection to ground which has minimal inductive impedance at very high frequencies.

Although this invention has been described with respect to a particular embodiment thereof, it is not to be so limited as changes and modifications may be made therein which are within the full intended scope of the invention as defined by the appended claims.

What is claimed is:

l. A socket structure for devices having contact prongs comprising a cylindrical base of insulating material, said base having recessed contacts cylindrically arranged on one flat surface thereof and projected contacts cylindrically arranged on the other fiat surface thereof, a ringshaped plate of conducting material, said plate having a plurality of projections on its peripher the number of said projections being less than the number of projected contacts, the projections of said plate being in contact with certain of said projected contacts, a button condenser having a metallic shoulder as a connection to one electrode of said condenser, said con lenser having means for connecting its other electrode to ground, and said condenser being integrally connected to said plate by said shoulder securely fitting in said plate.

2. A socket structure for devices having contact prongs comprising a cylindrical base of insulating material, said base having recessed contacts cylindrically arranged on one flat surface thereof and projected contacts cylindrically arranged on the other flat surface thereof, a ringshaped plate of conducting material, said plate fitting inside the cylinder formed by said projected contacts and having a plurality of projections on its periphery, the number of said projections being less than the number of projected contacts, the projections of said plate being in contact with certain of said projected contacts, a button condenser having a convex metallic shoulder as a connection to one electrode of said condenser, means for connecting the other electrode of said condenser to ground, and said condenser integrally connected to said plate by snapping said shoulder into said plate.

References Cited in the file of this patent UNITED STATES PATENTS 2,259,740 Del Camp Oct. 21, 1941 2,427,563 Lavoie Sept. 16, 1947 2,496,095 Kallmann Jan. 31, 1950 2,625,582 Hiebel Jan. 13, 1953 

